The reputation of Roundup, whose active ingredient is the world’s most widely used weed killer, took a hit on Tuesday when a federal court unsealed documents raising questions about its safety and the research practices of its manufacturer, the chemical giant Monsanto.

Roundup and similar products are used around the world on everything from row crops to home gardens. It is Monsanto’s flagship product, and industry-funded research has long found it to be relatively safe. A case in federal court in San Francisco has challenged that conclusion, building on the findings of an international panel that claimed Roundup’s main ingredient might cause cancer.

The court documents included Monsanto’s internal emails and email traffic between the company and federal regulators. The records suggested that Monsanto had ghostwritten research that was later attributed to academics and indicated that a senior official at the Environmental Protection Agency had worked to quash a review of Roundup’s main ingredient, glyphosate, that was to have been conducted by the United States Department of Health and Human Services.

The documents also revealed that there was some disagreement within the E.P.A. over its own safety assessment. The files were unsealed by Judge Vince Chabria, who is presiding over litigation brought by people who claim to have developed non-Hodgkin’s lymphoma as a result of exposure to glyphosate. The litigation was touched off by a determination made nearly two years ago by the International Agency for Research on Cancer, a branch of the World Health Organization, that glyphosate was a probable carcinogen, citing research linking it to non-Hodgkin’s lymphoma.

Court records show that Monsanto was tipped off to the determination by a deputy division director at the E.P.A., Jess Rowland, months beforehand. That led the company to prepare a public relations assault on the finding well in advance of its publication. Monsanto executives, in their internal email traffic, also said Mr. Rowland had promised to beat back an effort by the Department of Health and Human Services to conduct its own review.

Dan Jenkins, a Monsanto executive, said in an email in 2015 that Mr. Rowland, referring to the other agency’s potential review, had told him, “If I can kill this, I should get a medal.” The review never took place. In another email, Mr. Jenkins noted to a colleague that Mr. Rowland was planning to retire and said he “could be useful as we move forward with ongoing glyphosate defense.”

The safety of glyphosate is not settled science. A number of agencies, including the European Food Safety Agency and the E.P.A., have disagreed with the international cancer agency, playing down concerns of a cancer risk, and Monsanto has vigorously defended glyphosate.

But the court records also reveal a level of debate within the E.P.A. The agency’s Office of Research and Development raised some concern about the robustness of an assessment carried out by the agency’s Office of Pesticide Programs, where Mr. Rowland was a senior official at the time, and recommended in December 2015 that it take steps to “strengthen” its “human health assessment.”

In a statement, Monsanto said, “Glyphosate is not a carcinogen.”

It added: “The allegation that glyphosate can cause cancer in humans is inconsistent with decades of comprehensive safety reviews by the leading regulatory authorities around the world. The plaintiffs have submitted isolated documents that are taken out of context.”

According to Cary Giguere, Agrichemical Program manager at the agriculture agency, the dramatic rise in glyphosate use was a result of increased cover cropping on cornfields, where herbicides like glyphosate are used for what they call the “burn-down,” or killing of the cover crop,” before corn planting begins in the spring. Learn more: regenerationvermont.org/gmo-corn-to-blame-for-soaring-pesticide-use/... See MoreSee Less

The Chilean government, facing skyrocketing rates of obesity, is waging war on unhealthy foods with a phalanx of marketing restrictions, mandatory packaging redesigns and labeling rules aimed at transforming the eating habits of 18 million people. Nutrition experts say the measures are the world’s most ambitious attempt to remake a country’s food culture and could be a model for how to turn the tide on a global obesity epidemic that researchers say contributes to four million premature deaths a year. Could this be a model for the U.S.? regenerationvermont.org/they-slayed-tony-the-tiger-chiles-war-on-obesity-took-cartoon-icons-off-j...... See MoreSee Less

Gov. Phil Scott sketched out a plan at a dairy conference Thursday that could include making money from the pollutant plaguing Vermont’s waterways — phosphorus.

👉Regeneration Vermont’s take by Michael Colby:Any attempts to seriously address the dairy/phosphorus/water quality problems must begin with turning off the pollution spigot: the vastly unsustainable amount of manure created by Vermont’s 135,000 mostly confined cows.But getting rid of farms is not the solution. Rather, we need to transition away from the industrial, commodity model that is holding all of Vermont hostage – not just the dairy farmers who are getting less than the cost of production for their milk, but also our environment, our culture, and – of course – our cows. Read more of our thoughts and the article on our website: regenerationvermont.org/scott-remove-phosphorus/... See MoreSee Less